General 1967-2002 F-Body Tech For general F-Body discussion that does not fit in any other forum.
For F-Body Technical/Information Discussion ONLY

1997 Z28 Overheating

Old 07-12-2019, 07:07 PM
  #1  
Registered User
Thread Starter
 
Join Date: Jul 2019
Posts: 3
1997 Z28 Overheating

Hello, I recently got my water pump, alternator and a couple of other things replaced on my car from Tom Bell Chevy dealership. Before I got all of that replaced my car wasnít overheating but after driving it for possibly less then two weeks itís been showing as itís overheating. The mechanic is saying air is getting into the system and it might be a head gasket problem does that sound right or was it something he could have possibly caused? My car never had a overheating problem but now it does are they just trying to get more money out of me? This is what the dash looks like but it goes into the red zone. Also the mechanic replaced the thermostat so that shouldnít be the problem.

Functionsz213 is offline  
Old 07-12-2019, 07:08 PM
  #2  
Registered User
Thread Starter
 
Join Date: Jul 2019
Posts: 3
Re: 1997 Z28 Overheating

Any advice helps thank you
Functionsz213 is offline  
Old 07-12-2019, 07:38 PM
  #3  
Super Moderator
 
Injuneer's Avatar
 
Join Date: Nov 1998
Location: Hell was full so they sent me to NJ
Posts: 67,282
Re: 1997 Z28 Overheating

If they didn’t correctly bleed the air out of the LT1’s “reverse flow” (heads get cooled first) cooling system, it can overheat.

Air can also enter the system if the overflow line from the radiator fill neck to the reservoir is cracked, preventing the vacuum in the radiator from pulling coolant back from the reservoir as the system cools down. With the radiator completely cooled down, take the radiator cap off and see if the radiator is full to the very top. If it isn’t, good chance the hose or the metal pipe it connects to under the battery has a leak in it (or the radiator itself).

A pressure cap that doesn’t hold 18 PSI can cause overheating, when the coolant boils.

Do both fans run on low speed when the A/C is turned on, or when the coolant temp reaches 226įF? Do both fans move to high speed when the coolant temp reaches 235įF (pretty much the hashmark just to the left of the needle in your picture)?

There are two coolant temp sensors - one in the driver side head for the gauge, the other in the water pump housing for the PCM (which controls the fans). Shoebox has a test procedure for the sensors and circuits - see item #20 on this page - note there are several very useful articles on the cooling system operation and problems:

4th Gen LT1 F-Body Tech Aids
Injuneer is offline  
Old 07-12-2019, 07:40 PM
  #4  
Super Moderator
 
Injuneer's Avatar
 
Join Date: Nov 1998
Location: Hell was full so they sent me to NJ
Posts: 67,282
Re: 1997 Z28 Overheating

PS: the thermostat has to be on specifically for the LT1. Can't use a generic SBC t'stat.

http://shbox.com/1/tstat.jpg

And Yes, a blown head gasket can cause overheating.... and overheating can cause a blown head gasket.

Last edited by Injuneer; 07-12-2019 at 07:43 PM.
Injuneer is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
dirtgar
LT1 Based Engine Tech
21
10-04-2010 11:01 AM
Bowen292
LT1 Based Engine Tech
6
06-26-2007 11:39 AM
chuckt619
General 1967-2002 F-Body Tech
4
09-12-2005 01:28 PM
shaqdaddy
LT1 Based Engine Tech
7
09-01-2004 09:13 PM


Thread Tools
Search this Thread
Quick Reply: 1997 Z28 Overheating


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.